More information at http://www.arch.usyd.edu.au/~thorsten/lisp/lisp.html (This link is dead.)
I don't see licensing information on the web site, but given that the G in GCL stands for "GNU", I'm assuming for the moment that it's free.
Documentation for Gcl-Tk can be found at http://olympus.het.brown.edu/doc/gcl-doc/gcl-tk.html/gcl-tk_toc.html (yet another dead link). Presumably Lisp-Tk reimplements this interface for other CLs, so this doc is useful in evaluating whether it's worthwhile to try to dredge up and revive Lisp-Tk.
So, does anybody have a copy of this, or a current link?
It's included in: http://www.pmsf.net/cmucl/binaries/old/cmucl-18a.x86.linux.source.tgz (which now also is dead).
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